Specific Inhibition of the Hydrogenolysis of Benzylic C−O Bonds Using Palladium Nanoparticles Supported on Nitrogen‐Doped Carbon Nanofibers

Palladium nanoparticles supported on 5 %‐nitrogen‐doped, herringbone‐type carbon nanofibers (Pd/N‐CNF‐H), which are prepared by thermally decomposing [Pd2(dba)3⋅CHCl3] (dba=dibenzylideneacetone) in toluene in the presence of N‐CNF‐H, were found to be an efficient catalyst for the chemoselective hydrogenation of alkenyl and nitro moieties in benzyl‐protected alcohols and carboxylic acid derivatives with high turnover frequencies: the hydrogenation reactions of these functional groups proceeded smoothly even at ambient temperature under atmospheric H2 pressure, and the benzyl protecting groups in the molecules remained intact. Moreover, the recovered Pd/N‐CNF‐H catalyst could be reused without loss of its catalytic activity or chemoselectivity. The Pd/N‐CNF‐H catalyst also acted as an effective hydrogenation catalyst for the reduction of aromatic ketones to the corresponding benzyl alcohol derivatives with good to high product selectivity. Situation: immobilized: The catalytic activity of palladium nanoparticles towards hydrogenolytic cleavage of benzylic C−O bonds is effectively eliminated by immobilizing on nitrogen‐doped, herringbone‐type carbon nanofibers. The result is a chemoselective catalyst for the hydrogenation of alkenyl and nitro functionalities that is highly tolerant to benzyl protecting groups present in molecules.